Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8658d2604db8b85…

MALICIOUS

PDF

79.4 KB Created: 2021-09-16 14:38:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9566fb2cbffb68eeeb62442c2020f981 SHA-1: b694a103b93ba9e22dc8923a4b0d636ef0234c6e SHA-256: d8658d2604db8b855ab0fbb7e6eeac8aa21acb25a05b31f56f818f8cfd6d5cb5
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file that contains embedded JavaScript, indicating a potential for malicious execution. It also hosts numerous links, many of which point to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of its attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://casms.org/atts/news-files/file/18540030347.pdf In PDF document text
    • http://startmatbaa.com/userfiles/file/25662230712.pdfIn PDF document text
    • https://hr-serdahel.hu/images/file/nonesuvozijabiwawevogariz.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614046bf8f16c---4468257094.pdfIn PDF document text
    • http://plnjl.com/userfiles/files/mizajadimixufu.pdfIn PDF document text
    • http://milkexim.ru/imgeditor/file/fukajenazunijofipij.pdfIn PDF document text
    • http://sjmhospital.org/files/js/ckfinder/userfiles/files/fagafuravoruj.pdfIn PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/e0cd013cd6877e84050d55aee00639e8/36009281384.pdfIn PDF document text
    • http://accessibilite-salle-eau.com/ckfinder/userfiles/files/71508193178.pdfIn PDF document text
    • http://fmmvn.net/userfiles/files/kusinugovosorifupajav.pdfIn PDF document text
    • http://wamer.org/userfiles/file/92725630152.pdfIn PDF document text
    • http://sinoscaform.com/upload/ckimg/files/202109011603528521.pdfIn PDF document text
    • https://najlepsze-w-polsce.pl/uploads/540472050.pdfIn PDF document text
    • https://la-klamm.org/userfiles/file/newip.pdfIn PDF document text
    • http://www.aceitunasdelguadalhorce.es/ckfinder/userfiles/files/fulukixalixixemubiwenopi.pdfIn PDF document text
    • http://yugang360.com/upload_fck/file/2021-9-4/20210904150400443220.pdfIn PDF document text
    • http://artiguardia.pl/userfiles/file/45116650988.pdfIn PDF document text
    • http://orourkelawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/76062574854.pdfIn PDF document text
    • https://xinpayflow.com/ckfinder/userfiles/files/jokudigoxozowoduside.pdfIn PDF document text
    • http://panel2conso.com/userfiles/file/39842310726.pdfIn PDF document text
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/1fd0423ca04ac24595d5c98b4f74d22a/44685626129.pdfIn PDF document text
    • http://stoka-saarlouis.de/userfiles/file/xosesidaxudikupig.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=download+mp4+to+mp3PDF link annotation
    • https://b2cdemo.tickets.com/content/files/naditobebi.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d337.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD337 10400 bytes
SHA-256: 0a440b7575a82c6459293e9d4ccec81606503886488b717578e585b4e5275781
font_01_sfnt_off0000ead0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000102e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102E2 18148 bytes
SHA-256: d26b5fa8946fa8960740f8aa044c67c35d7e92ea9d979eec98d9d9c6dfb1e78a